Electrical control means



Sept. 12, 1939. A. L. SMITH V ELECTMCAL CONTROL MEANS Filed sept. 23. 195e NVENTOR` TTORNEY y* Patented Sept. 12, 1939 UNITED STATESI PATENT OFFICE 2,172,643 ELECTRICAL 'CONTROL MEANs Arthur Leroy Smith, Bryn Mawr, Wash.

Application September v23, 1936, Serial No. 102,080

9 Claims. (01.'236-1) This invention relates to electrical control means for an air conditioning, air circulating and water heating plant and the primary Object of this invention is to provide central control 5 means which will make itpossible to secure any desired operation or sequence of operations of the air conditioning, air circulating and water heating plant by a simple and easily understandable setting of the control means.

l0 Another primary object of the invention is to provide a control means of this nature which is substantially foolproof, which will safeguard the air conditioning, air circulating and water heating plant with which it is connected and which 15 will make it substantially impossible for a Auser `of the plant to bring about undesirable air conditioning.

Another object of the invention is to provide a central control means of this nature in which 'I 20 all of the ymanually controlled circuits are controlled by a single, easily operable, switch member movable to selective positions to selectively operate different' control circuits or different combinations of control circuits.

25 Another object oi the invention is to provide novel means for controlling day and night operation of a plant of this nature, said means comprising manually operated devices for lowering the setting of thermostat means for night temperatures at the time of retirement, and clock operated means for raising the setting of the thermostatic means for day temperatures at a predetermined set time in the morning without requiring any calculation on the part of the user as to the number-oi hours elapsing between the time the device is setfor night temperatures and the time oi' return to the day temperature level.

Another Object oi' the invention is to provide a control means which makes it possible to supply energy to the ignition circuit of an oil burner without operating the motor which supplies fuel to said burner, thus making it possible to inspect and adjust the burner ignition means while said 4, ignition means is supplied with current without simultaneously discharging oil from 'the burner.l

Other and more speciilc objects of the inventiony will be apparent from the following description taken in connection,with the accompanying drawing.

The term air conditioning or conditioning of air is herein used as including heating, cooling,

humidifying, cleaning and purifying of the air. This control is .suitable for. u se in connection with a plant where the air is to be heated, cooled, Washed, humidied, dried out, cleaned oi' smoke, dust, odors, and the like, treated in any othe way and circulated as desired.

' In the drawing Figure 1 is a diagram of elec- 60 triclcontrol means embodying invention,

showing the same in connection with air conditioning, air circulating and water heating means. Fig. 2 is a small scale diagrammatic view illustrating diagrammatically vone arrangement with 5 The numeral 6 designates an oil atmomizing'15 burner nozzle of a type commonly usedin connection with oil burners. l designates an oil pump and 8 is a motor adapted to drive said pump tol supply oil or like fuel to the burner nozzle. 8 is a conventionalv stack switch posi- 20 tioned in the stack 4of a furnace where it is subject to temperature variations of the d ischarging -ilue gases. The stack switch 9 has a transformer relay set embodied therein and indicated generally by I0. In addition tothe transformer relay set I0 the stack switch 9 is providedwith the usual time delay safety means, not shown, for stopping the burner motor 8 in the event temperature conditions in the stack do not become normal. within a predetermined 36 period of time after the starting circuits to the burner motor are closed. As this time delay safety means is of well 'known construction and as it is not a part of this invention it is not herein shown and described in detail. v

Numerals II, I2 and I3 designate generally a I limit switch, a fan switch and an aquastat switch respectively. These switches are all thermostatically operated. Il designates generally a' transformer relay set, I5 a damper motor, I6 a by- 40 pass-damper mechanism, I-'l a solenoid controlled water valve, I8 a fan motor, I9 a Ian or blower driven by the motor I8 and 20 amechanical refrigerating mechanism or compressor connected by'means, including a solenoid operated 45 clutch lmechanism 2|, with the fan motor I8.

Each switch II, I2 and I3 is herein illustrated vas comprising -a lai-metallic thermostat member 29 having a coi! 35' thereon. Thermostat member 29' is connected by means 3l with a switch arm' 32 which is interlocked with an inclined switch arm 33. In the event too much current 5 is passed through coil 35' it will produce mo'vement of thermostat member 29', lifting switch arm 52, breaking the circuit between arms 32 aand 33 vand allowing arm 33 to drop' down. The arm 3,3 must be manually re-set in contact with arm 32 after the switch provided by these arms has been opened. The arms 33 are connected with the respective motors 5 and I5 by conductor means 34.

vIn addition to the transformers of the relays I5 and I4 other transformers are provided in the circuit, as follows; a burner` ignition step-up transformer comprising primary winding 35 and secondary winding 35, a humidity circuit stepdown transformer comprising primary winding 31 and secondary winding 35, a damper motor stepdown transformer comprising primary winding 39 and secondary winding 45. The high`voltage secondary winding 55 of the ignition transformer is connected by conductors 4I and 42 with ignition points 43 of conventional type.

. The control mechanism. 5 comprises a manually operable switch blade 44 which is mounted on a pivot 45. The switch blade 44 has 'an 0113" position in'which it is shown in the drawing. This blade 44 is adapted to selectively make electrical Acontact with contact members 45 tc 55 inclusive as it is moved angularly on pivot 45. Contacts 45 and 54^are electrically connected with each otherby conductor 51. Contacts 45, 55 and 52 are electrically connected with each other by conductors 55. Contacts 53 and 55 are electrically` connected with each other by conductor 59. Contacts 41 and 49 are electrically connected with each other by conductor 59. 'Ihe contacts 45 to 53 are arranged in pairs, as follows; Contacts 45-41,

contacts -49, contacts 55-5I and contacts 52-53 are paired. Contacts 54-55 are also paired, and in addition, a,third contact 55 is provided in this group. 'I'he switch member `44 is arranged to simultaneously contact the two contact members of each pair and the three contact members of the group 54-55-55.

A humidostat 55 is provided in the control mechanism 5. This humidostat 55 is illustrated as comprisingv a humidity responsive device 5I.

, adapted to open and close a switch-52. Also there is provided in the control mechanism, a dual or double thermostat 53. This dual thermostat is illustrated as comprising a day control temperature responsive device orA thermostat 54' and a night control temperature responsive device or thermostat 54'. A mercury tube switch 55 is mountedon a pivot 55 on control mechanism 5. This mercury tube switch is adapted to be angu- 50 larly moved into one operative position, as shown in the drawing, by engagement of an arm 51 of a clock means 55 with a lever 59- of the mercury" tube switch 55. 'Ihe mercury tube switch' 55 is adapted to b e tilted or angularly moved to o5 another operative position by manually controlled mechanical means in the form'of a link 15 connectingsaid switch 55|with a lever arm 'Il which is pivoted on a pivot 12 and positioned immeditely below the switch lever 44 when said switch lever 44 is in the open or "oil" position, whereby said lever 1I may be moved downwardly by de- 1, pressing the switch lever 44 below the "011" position. .Preferably a visual sig'nal meansfwill be" provided to indicate whether lever 1I is in the day ornightpolsition. This may be in the nature of a colored mark 13, see dotted lines, adapted to be covered by the lever 1I in vone position., When the lever 1I is thus moved downwardly the switch 55 will be oscillated in a clockwise direction on -pivot55 into a diierent operative position from 5 that shown in the drawing.

The-mercury tube switch 55 is provided at the two ends with the usual two pairs of contacts 14 and 15. One of the contacts 14 is connected by a conductor 15 with suitable switch means 11 10 operated by the night thermostat memberv 54. The other contact 14 is connected by a conductor 15 and conductor 59' with contacts 49 and 41. One of the contacts 15 is` connected by conductor 19 with suitable switch means 85 operated by the 15 day thermostat member 54. 'Ihe other contact 15 is connected by conductor 5I with the conductor 15 which leads to contacts 49 and 41.

yThermostat circuit The source of energy for the thermostat circuit is the secondary winding 35 of the stack switch relay set I5. From this Winding 35 the thermostat circuit may be traced as follows: along a conductor 51 to thermostat members 54 and 54. 25

, Then, ii thermostat member is in closed circuit position, through said member 54, through switch 55, along conductor 19,*through contact points 15, if they are closed, then along conductor members 5I and 15 ,to contacts 49 and 41. If`switches 11 30 and 14 are closed and either one or both of switches 55 and 15 open then the circuit will be through thermostat member 54', through switch 11, along conductor 15, through contacts 14 and along conductor 15 to contacts 45- and 41. If thel 3- switch member 44 is in contact with either contact member 41 or 49 then the thermostat circuit will be .from contact 41 or 49, through switch blade 44, along conductors 52, 55 and 59, through switch blade 24v of limit switch II, along cono ductor 95, through winding of electromagnet 25 of relay set I5 and back to secondary winding 35 of the transformer of stack switch relay set I5. This completes the thermostat circuit.

Aquastat circuit 45 will be along switch 44, along conductors 52, 55 u and 53, along blade 24 oi' limit switch II, along conductor 55 through winding of electromagnet. 25 of stack relay I5 and back to winding 3l of stack relay I5. 'I'his completes the aquastat cirvcuit and provides for a controllo! the heating of w water.

Humidity circuit' 'I'he source of renergy for the humidity circuit is the secondary winding 35 of transformer 31--33. From winding .35 this circuit may be traced along', 55 conductor 55, through switch 52 of humidostat 55. along conductors 55 and 52, through winding of solenoid 53 and along conductor 54 back to winding 55. This completes the humidity circuit and provides for operation of valve 54'. noted that the operation of the humidity circuit is not dependent in any way on temperature but said humidity 'circuit is interconnected with vthe fan circuit. as will later be apparent.

It will be notedthat conductor 52 is common to 1s It is t0 be 70.

substantially all of the control circuits-which are manually controlled. It will also be noted that the limit switch I I is interposed in both the thermostat circuit and the aquastat circuit. It will further be noted that the opening of the limit switch II does not eiect the closing of the fan circuit, the common return o`f which is a part of the thermostat and-aquastat circuits. 'I'his limit switch is` normally closed, but will open either of these circuits in response to an overheated condition of the heating plant with which lt is associated.

-Fan motor circuit The source of energy for the fan motor circuit is' the secondary winding 30 of the transformer relay set I4. From this secondary winding 30 the fan motor circuit may be traced along conductors 93 and 94 to contacts 53 and 55 which are connected with each other by conductor 59, thence Auxiliary fan, control circuit The source of energy for the auxiliary fan control circuit is the same as for the manually controlled fan control circuit, namely, the secondary winding 30 of transformer relay set I4. From this winding 30 the thermostatically controlled auxiliary fan control circuit is along conductors 93 and 95, through switch blade 24 of thermostatic fan switch I2, along conductors 95' and 89 and through the winding of the electromagnet 25 back to the secondarywinding 30 of the transformer relay set I4. This thermostatically controlledauxiliary fan control circuit provides means for operatingrelay rI4 and keeping the fan motor I8 energized if the temperature of the fan switch is above a predetermined minimum even though the manually controlled fan -circuit is open.

also serves as a source of energy in the control circuit for the cooling means including the refrigerator device 20 and the valve 84',- For the refrigerator device 20 this circuit is from the secondary winding 30 of transformer relay set I4, along conductor 91, through winding oi clutch control solenoid 98, along conductor 99 to contact 59, thence along switch 44, if said switch is closed on 56, along conductors 82, 88 and 89 and through the winding of electromagnet 25 of relay set I4 back to source oi' energy 30. This circuit provides for simultaneously energizing the motor I8 and engaging the clutch means 2| when switch 44 vis positioned on contacts 5 5 and 55. Also upOn closing this cooling circuit. a circuit to solenoid valve 84' is closed due to the closing of switch means 21-28 of relay I4. This circuit is as follows: From secondary transformer coil 38, which will be energized at this time, the circuit is along conductor 85 through humidost'at switch 92, providing it is closed, along con` ductors 85 and 82, through the winding of electromagnet 83 and along conductor 84 back to winding 38. This opens valve 84 and provides water for cooling as well as putting reirigerating means 20 into operation.

Damper control circuit 'Ihe source of` energy ior the .damper control circuit is the secondary winding 40 of the damper motor transformer. From this source 40 the circuit is along conductor |00 and brush I0Il to two cam switches |02 and |03, which are operated by the motor I5 through any suitable speed reduction mechanism I5'. One of these cam switchesis always in closed circuit and the other is always in open circuit position. If the cam switch |03 is closed and cam switch |02 open, as shown, then the circuit is along conductor |04 to contacts 52-50-48, thence through switch 44 if it is closed on 52, 50 or 48, thence along conductor 82' and conductor |05, through the windings of motor I5 and alongconductor |06 back to transformer winding 40. If cam switch |02 is closed and cam switch |03 open then the circuit .will `be through cam switch |02, along conductor |01 to contacts 54 or 48, said contacts being connected by conductor 51, then through switch 44, if it is closed on contact 54 or 48, thence 'along conductors' 82 and |05, through the windings of motor I5 and along conductor |06 back to the transformer winding 40. These damper circuits provide a control for moving a by-pass damper into one position to deliver warm air at a desired location, as to the rooms of a house, when the circuit is closed through cam switch |02 and y for moving said bypass damper into another position to by-pass the warm air and deliver it to a different location, such as out of doors or into a basement or drying room and avoid delivering it to the rooms of a house, when the circuit is closed through c'a'm switch |03. It is to be noted that each operation or cycle of the cams |02- |03 is limited to substantially 180 degrees.

The by-pass damper connection, shown somewhat diagrammatically, may comprise a crank I08- on the shaft of cams |02-|03. The crank |08 is connected by a connecting rod |09 with a lever IIO. The lever I-I0 is connected with a'by passv damper III through a common pivot ii2. The by-pass damper III is adapted to be .moved into a position, as shown by full lines, to close a by-pass opening I|4 from a heating plant to the atmosphere or into another position, as shown by dotted lines, to close an opening II 3' between the plant and a warm air take ofi' bonnet I|3 at the top portion oi said heating plant. The bonnet I|3 is preferably connected by suitable hot air conduits, one of which is shown, with rooms to be heated. The by-pass opening |I4 may open to the outside atmosphere so that heat which is generated in hot weather incidental to the heating of water for domestic use may be liberated out of doors to avoid heating the rooms connected with bonnet Ii3. Also in some instances it is desirable' to connect by-pass opening I I4 with a drying room or laundry room in the basement of a home or apartment building or to permit hot air from lay-pass opening ||4 to discharge directly A into a basement which is used as a drying room damper means thus make it possible-to use the down transformers.

operate on approximately twenty volt current. Other source of supply circuits. preferably operating on a higher voltage, as 1'10 to 220 volts, are provided as hereinafter set forth.

Ignition circuit l Current, preferably at 110 to `120V volts, is sup- .plied through source of supply conductors III and I I6 to switch members' 21 and 28 of stack switch'relay I0. When these switch members 21 Aand 28 are in-closed position a circuit is oompleted from conductor H5, through blade 21, along conductor |I1, through primary winding 36 of the ignition,l transformer and along conductor II8 and switch blade 28 to source of supply conductor IIC. This energizes thestep up ignition transformer and delivers current at high voltage suitable for igniticnpurposes through conductors 4|A and 42 tothe ignition points v43 when switch 21--28 Aof relay I0 is inV closed position.

Burner motm` circuit The burner conductor |I5 through switch blade 21 of relay I0, when closed, along conductors II1 and IIQ, through coll of burner motor thermal cut out, through switch members 32 and 33, along I conductor 34, through the windings of burner motor 8 and along conductor II8 and switch blade 28 oi relay I0 to source of supply conductcr IIS. This provides current for Vthe burner motor 8 when the switch 21--28 of` relay I0 isI closed. A

' Fan motor operating circuit The wires II5 and II8 also constitute an outside source of energy to the transformer of the relay set I4 and to the fan motor I8. The circuit to the ian motor is from source 4oi supply wire II5, through switch blade 21 of relay set I4, it being assumed that switch 2,1-28 is closed, along conductor |I5 through thermal cut out 30'- 32-33 of motor I8, along conductor 34 through motor I8 along conductor II8' and through blade 28 of relay I4 to source of supply conductor IIB. This provides a circuit, controlled by electromagnet 25 for energizing .motor I8 to drive fan i9 and operate cooling means 20.

It is to be noted that the source of supply wires II5' and II6' are also connected with the pri- .4

mary winding 31 of the humidity circuit transformer and source of supply wires II5, IIB are connected with the primary winding 33 of the damper motor transformer.

When the switch member 44 is in the "ot! position, as shown in the drawing, all of the devices controlled Vby the control circuits. vwill ordinarily be inoperative. .There may be one exception to this however in the event the heating plant has been in operation the thermostatic fan .switch I2, which is positioned in the bonnet portion of the heating plant, may remain closed or 'may intermittently open and close due to the These circuits preferably motor circuit may be traced from heat remaining in the cinbustion chamber and may thus keep the fanjloperating either intermittentlyor continuously until the heating plant cools oi. f

When switch member- 44 is moved to the on vposition in contact with contact members 46 and 41 this completes the thermostat circuit through contact 41 as respects switch 45. If at this time the thermostat circuit is closed through either thermostat member 64 or 54 the circuits to the burner motor 8'and ignition transformer 36-35 -will be closed thus putting the burner 6 into operation. A

The closing of switch 44`by reason of contact with member 48 completes the circuit 4to the damper motor I5 in so far as switch 44 is concerned. If damper III is open as respects bonnet II3 .and closed as respects by-pass escape opening II4 and cams |02 and |03 are in the position shown, this circuit will be broken at the location of cam |02 and the damper motor-Will not be energized. If the damper III is in the opposite position to -o pen by-pass |I4 and close the passageway to bonnet IIS then the circuit through cam |02 will be closed and motor I5 will be energized long enough to Aangularly move the cams |02 and |03 through substantially |80 degrees thus closing -the by-pass I|4 and opening the passageway to the heating bonnet I I3. This provides for always properly positioning the by-pass damper III to deliver heat to the bonnet I I3 and to" close the by-puss II4 when switch 44 is in the on position. This same action takes place when the switch 44 is moved onto the contact member 54, due to the fact that contacts 54 and 46 are electrically connected by conductor 51.

It is to be noted that when switch 44 is positioned on contact 45 it is also positioned on con` tact 41 completing a thermostat circuit and '1ndicating a demand for heated air. For this position the by-pass damper will be positioned to deliver heated airV to bonnet II3. If switch 44 is. positioned on contact 54, and at the same time on contacts 55 and 50, this will indicate ademand for a circulation and cooling of the air. For this position of the switch member 44 the by-pass damper will also be positioned to deliver to the bonnet II3 air which has been t cooled by reason of the operationI of valve 84' or refrigerating means 20 or both. Also the ian circuit to relay I4 will be completed by reason of contact-between switch 44 and contact member 55 insuring continuous operation of the fan motor I8 for this position and also-supplying current to the primary winding 31 of the humidity circuit transformer, whereby, if the humidostat switch 62 is closed, water may be allowed to ilow through valve 84' to humidifying means 84" in the heating plant 4 or passageways ccnnected therewith.

If switch 44 is moved onto contacts 48-49, then all circuits are .the same as when switch 44 is on contacts 48-'41, except by-pass damper is open -as respects by-pass opening II4 and closed as respects bonnet I I3 to permit by-passing of heated air. For this position the thermostat circuit will be closed and the damper motor.

circuit through cam |03 will be closed positioning the damper III to close passageway |I3 and open by-pass opening II4. This makes it possible, for instance, to deliver heat through bypass |I4 to the basement or to a clothes drier or to the outside. If switch 44 is moved onto contacts 50, 5I the contact with 5.0 will keep the lay-'passl damper 'I I I open as respects the by-pass II4 in the same manner as just described in connection with contact 48 it being noted that contacts 48 and 50 are electrically the same. Contact of switch member 44 with contactmember 5I completes the aquastat circuit through the aquastat switch I3 instead of through the -by-pass damper III open as respects the by-pass I I4 in the same manner as just described in connection with contacts 48 and 50 due to 48, 50 and 52 being electrically the same. The positioning of switch member 44 on contact member 53 completes the fan circuit. The completing of this circuit keeps the fan operating continuously while the by-pass damper is open as respects the bypass II4. This makesit possible to remove foul air fromthe house without operating the burner 6. While the fan is thus operating the burner B will be shut off as the circuits through the termostat means 63 and aquastat switch I3 -are broken.

The day and night control mechanism connected with dual thermostat 63 makes it easy to shift from day to night control and vice versa without requiring any calculations on the part of the user and with no liability of error. At the time of retirement at night the user depresses switch-lever 'II through the operation of 'switch member t4 tilting mercury switch 65 and rendering the night thermostat operative. At the hour which has been selected for increasing the temperature of the house in the morning the arm 6l of clock 68 .will tilt the mercuryswitch 85 in the opposite direction and transfer control to the day thermostat. Y

From the foregoing description it will be seen -that this control system provides a combination by-pass damper circuits are combined in such a' way that the by-pass damper is always correctly positioned to provide for the delivery ot heated air to the house when the switch member is moved to the house heating or on" positionand will always be correctly positioned to prevent the delivery of heatedair to the rooms of the house when the switch 44 is moved onto contacts 48-49, BIL-EI, or 52-53 to open the by-pass damper or to heat water in hot weather or to ventilata the house without heating the same. The circuits are further combined and arranged in such a manner that cooling can be attained without operating the burner and with the by-pass damper being automatically moved to the correct position and so that the proper humidincation oi the air can alwaysbe attained without delivering too much water through the valve 84'. Y

The foregoing description and accompanying drawing clearly disclose a preferred embodiment of my invention but it will be understood that this disclosure is merely illustrative and -that such changes in the invention may be made as are fairly within the scope and spirit ofthe following claims. f

I claim; 1

1. In electric control means of the class described, a control unit; a plurality of control ciruits connected with said control unit; a manually operable control switch selectivelycontrolling said control circuits; a dual thermostat comprising a night thermostat member and a day thermostat member, said two thermostat members having cir,-

cuit means adapted to electrically connect said thermostat members with said control switch;

time switch means adapted selectively to electrically connect either of said thermostat members with said control switch means; clock meansV adapted to move said time switch means into electrically connected position as respects said day thermostat member; and switch moving means connecting said time switch means with said manually operable. control switch whereby said time switch may be'moved by operation of said manually operable control switch into electrically connected relation with said night thermostat member.

2. In electric control means of` theclass described,.a fan providing a circulation of air; a fan motor; va fan motor control rcircuit; an oil burner; a furnace heated bysaid oil burner; oil burner circuits; manual control means connected with said fan motor Icontrol circuit and said oil burner circuits adapted to open said fan motor circuit and said oil burner circuits for the purpose of shutting down said oil burner and deenergizing said fan moto and a thermostatically controlled fan circuit sw tch in said circuits between said Ian motor and said oil burner controlled by the heat of said furnace and operable to energize said fan niot'or when said oil burner circuits and said fan motor circuit lare open due to the opening of said manual control means to maintain a circulation of air through the furnace after the oil burner becomes inoperative and until the furnace becomes cool.

3. In an ,electric control ymeans of the class de- A scribed, a thermostat circuit; heat generating 'means adapted to heat air and connected by hot air conduits with rooms to be heated and controlled byvsaid thermostat circuit; a by-pass control circuit; by-pass air control means governing the delivery of heated air from said heat generating means Ato the hot air conduits connected with the rooms, whereby heated air may be delivered to rooms to be heated or may be prevented from passing to said rooms and directed to other locations; switch means ior simultaneously closing said two circuits; and electrically actuated means in said by-pass control circuit for selectively positioning said by-pass `air control means upon the closing oi said circuits and determining whether or not heated air is to be'delivered to said conduits connected with said rooms.

4. In an electric control `means'of the class described, a thermostat circuit; heat generating means adapted to heat air and connected by hot air conduits with rooms'to be heated and controlled by said thermostat circuit; a thermostatically controlled switch in said thermostat circuit adapted to open and close said thermostat circuit; a by-pass `control circuit; a by-pass damper selectively controlling `the discharge of heated air from said Vheat generating means whereby said heated 'air may delivered to 75 rooms to be heatedor lmay be prevented from passing to said rooms and directed to otherV locations; electrically actuated means in said by-pass control circuit selectively positioning said by-pass damper; and manually operated switch means independent of said thermostatic switch `for simultaneously closing said two circuits to render said by-pass control circuit operative and selectively A position said by-pass damper to directheated air to said hot air conduits or to prevent passage o heated air to said hot air conduits.

5. In an electric control means of the class described, av thermostat circuit; heat generating means adapted to heat air and connected by hot air conduits with rooms to be heated and controlled kby said thermostat circuit; a thermostaticallycontrolled switch in said thermostat cirthermostat circuit and one branch of said bypass control circuit and another position in which it closes said thermostat circuit and the other branch of said by-pass control circuit; and a by-pass damper movable into a position to direct heated air into said hot air conduits when said thermostat circuit and one of said by-pass circuit branches is closed and movable into a position to exclude heated air from said hot air conduits when said thermostat circuit and the other bypass circuit branch are closed by said manually operated switch means.

6. In an electric control means for combined f air heating and water heating apparatus, heat generating means adapted to heat air and water and connected by hot air conduits with rooms to be heated :an aquastat circuit cooperating in the control of said heat generating means; an aquastat switch in said aquastat circuit responsive to the temperature of water heated by said heat u generating means; by-pass Adampermeans connected with said heat generating means movable into one position to direct heated air to said hot air conduits and heat the rooms connected therewith and into another position to exclude heated air .from saidhot air conduits whereby heating of said rooms may be avoided and at the same time water may be heated; -electric means for operating said by-pass4 damper means; by-pass damper control circuit means controlling said operating means adapted when closed to position said by-pass damper to exclude heated air from said conduits; and manually operable switch' means for simultaneously closing said aquastat;

circuit and said by-pass control circuit.

'1. In an electric control for air heating, water; heating and air circulating apparatus for use with a furnace housing which is connected with rooms by conduit means adapted to conduct air from said furnace housing tosaid rooms and by other conduit means adapted to conduct air from said rooms to saidi'urnace housing; heat generating means; va thermostat circuit adapted to cooperate in the control of said heat generating means; a

thermostatically operated switch in said thermostat circuit; an aquastat circuit also adapted to cooperate in the control of said heat generating means; a thermostatically operated switch in said aquastat circuit operated by the temperature of water heated by said heat generating means; bypass means adapted selectively to direct heated air to rooms connected with said air conditioning means or to divert heated air away from said rooms; by-pass control circuit means including a Y tively movable to close said thermostat circuit and said iirst mentioned branch of said by-pass control circuit to heat air and water and direct heated air to said rooms or to close said aquastat circuit and said last mentioned branch of said by-pass control circuit to divert heated air away from said rooms when water is being heated.

8. In an electric control.for air conditioning means for use with a furnace housing which is connected with rooms by conduit means adapted to conduct air from said furnace housing to said rooms and by other conduit means adaptedto conduct air from said rooms to said furnace housing; fan means connected with said conduit means; a fan motor driving said fan means: a Ian motor circuit controlling saidlfan motor; bypass damper means connected with said conduit means and movable into diilerent operative positions to direct circulating air to the rooms or to divert said circulating air away from the rooms; by-pass control circuit means embodying a plurality of branch circuits, one of which is operative when energized to position said by-pass damper means to divert air away from said rooms; and manually operable control switch means selectively movable to close said fan motor circuit and said branch circuit of said by-pass control circuit whereby the fan will be operated and air will be drawn from said rooms to ventilate said rooms without returning said airA to said rooms.

9. In an electric control for air conditioning means for use witha furnace housing which is connected with rooms by conduit'means adapted to conduct air from said furnace housing to said rooms and by other conduit means adapted to.

conduct air from said rooms to said furnace housing; air cooling means connected with said conduit means; fan means connected with said conduit means; afan motor driving said fan means;

'a fan motor circuit controlling said Ian motor; by-pass damper means connected with said conduit meansand movable into different operative positions to direct circulating air to the rooms or l to divert said circulating air away from the rooms; by-pass control circuit means embodying a plurality ofbranch circuits, 1one of which is operative when energized to position said by-pass damper means to direct air to said rooms; a cool-y ARTHUR LEROY sbarram' said 7o 

